package basic;

/**
 * @Author: 海琳琦
 * @Date: 2021/8/12 14:06
 */

class ListNode {
    int val;
    ListNode next;
    ListNode() {}
    ListNode(int val) { this.val = val; }
    ListNode(int val, ListNode next) { this.val = val; this.next = next; }
}

public class Title2 {

    public static void main(String[] args) {

    }

    private static ListNode addTwoNumbers(ListNode l1, ListNode l2) {
          ListNode head=null,tail=null;
          int r = 0;
          int sum;
          //都为空跳出训练
          while(l1!=null||l2!=null){
              int a = l1!=null? l1.val:0;
              int b = l2!=null? l2.val:0;
              sum = r + a + b;
              if(head==null){
                  head=tail=new ListNode(sum%10);
              }else{
                  tail.next=new ListNode(sum%10);
                  tail = tail.next;
              }
              r = sum / 10;
              if(l1!=null){
                  l1=l1.next;
              }
              if(l2!=null){
                  l2=l2.next;
              }
          }
          if(r!=0){
              tail.next = new ListNode(r);
          }
          return head;
    }
}

